Relationship between Fluid Flow and O2 Demand in Tissues in Vivo and in Vitro

1983 ◽  
Vol 27 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Roland A. Coulson
Keyword(s):  
Fluid Flow

scholarly journals O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
MI Khot ◽  
M Levenstein ◽  
R Coppo ◽  
J Kondo ◽  
M Inoue ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fluid Flow ◽  
High Throughput ◽  
Microfluidic Devices ◽  
In Vitro Models ◽  
Fluorescent Imaging ◽  
Cancer Tissue ◽  
Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p<0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

In Vitro Experimental Investigation of the Integrity of the Stem–Cement Interface

2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Vitro Experiment ◽  
Cement Interface ◽  
In Vitro Experiment ◽  
Mechanical Bonding

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.

In vivo and in vitro study of enamel fluid flow in human premolars

2020 ◽  
Vol 117 ◽  
pp. 104795 ◽  
Author(s):  
Rathirach Tanapitchpong ◽  
Ekachai Chunhacheevachaloke ◽  
Orapin Ajcharanukul
Keyword(s):  
Fluid Flow ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Embryonic nodal flow and the dynamics of nodal vesicular parcels

2006 ◽  
Vol 4 (12) ◽  
pp. 49-56 ◽  
Author(s):  
Julyan H.E Cartwright ◽  
Nicolas Piro ◽  
Oreste Piro ◽  
Idan Tuval
Keyword(s):  
Fluid Flow ◽  
Closed System ◽  
Biochemical Mechanism ◽  
Numerical Techniques ◽  
Biophysical Properties ◽  
Nodal Flow ◽  
Dynamical Simulations ◽  
Mechanical Rupture

We address with fluid-dynamical simulations using direct numerical techniques three important and fundamental questions with respect to fluid flow within the mouse node and left–right development. First, we consider the differences between what is experimentally observed when assessing cilium-induced fluid flow in the mouse node in vitro and what is to be expected in vivo . The distinction is that in vivo , the leftward fluid flow across the mouse node takes place within a closed system and is consequently confined, while this is no longer the case on removing the covering membrane and immersing the embryo in a fluid-filled volume to perform in vitro experiments. Although there is a central leftward flow in both instances, we elucidate some important distinctions about the closed in vivo situation. Second, we model the movement of the newly discovered nodal vesicular parcels (NVPs) across the node and demonstrate that the flow should indeed cause them to accumulate on the left side of the node, as required for symmetry breaking. Third, we discuss the rupture of NVPs. Based on the biophysical properties of these vesicles, we argue that the morphogens they contain are likely not delivered to the surrounding cells by their mechanical rupture either by the cilia or the flow, and rupture must instead be induced by an as yet undiscovered biochemical mechanism.

Review of the fluid flow within intervertebral discs - How could in vitro measurements replicate in vivo?

2016 ◽  
Vol 49 (14) ◽  
pp. 3133-3146 ◽  
Author(s):  
Hendrik Schmidt ◽  
Sandra Reitmaier ◽  
Friedmar Graichen ◽  
Aboulfazl Shirazi-Adl
Keyword(s):  
Fluid Flow ◽  
Intervertebral Discs ◽  
In Vitro Measurements

scholarly journals Finite element study of stem cells under fluid flow for mechanoregulation toward osteochondral cells

2021 ◽  
Vol 32 (7) ◽  
Author(s):  
Mehdi Moradkhani ◽  
Bahman Vahidi ◽  
Bahram Ahmadian
Keyword(s):  
Stem Cells ◽  
Shear Stress ◽  
Fluid Flow ◽  
Computational Simulation ◽  
Hydrodynamic Pressure ◽  
Mechanical Stimuli ◽  
Pore Architecture ◽  
Proliferation And Differentiation

AbstractInvestigating the effects of mechanical stimuli on stem cells under in vitro and in vivo conditions is a very important issue to reach better control on cellular responses like growth, proliferation, and differentiation. In this regard, studying the effects of scaffold geometry, steady, and transient fluid flow, as well as influence of different locations of the cells lodged on the scaffold on effective mechanical stimulations of the stem cells are of the main goals of this study. For this purpose, collagen-based scaffolds and implicit surfaces of the pore architecture was used. In this study, computational fluid dynamics and fluid-structure interaction method was used for the computational simulation. The results showed that the scaffold microstructure and the pore architecture had an essential effect on accessibility of the fluid to different portions of the scaffold. This leads to the optimization of shear stress and hydrodynamic pressure in different surfaces of the scaffold for better transportation of oxygen and growth factors as well as for optimized mechanoregulative responses of cell–scaffold interactions. Furthermore, the results indicated that the HP scaffold provides more optimizer surfaces to culture stem cells rather than Gyroid and IWP scaffolds. The results of exerting oscillatory fluid flow into the HP scaffold showed that the whole surface of the HP scaffold expose to the shear stress between 0.1 and 40 mPa and hydrodynamics factors on the scaffold was uniform. The results of this study could be used as an aid for experimentalists to choose optimist fluid flow conditions and suitable situation for cell culture.

scholarly journals Sanal Flow Choking in Nanoscale Fluid Flow Systems at the Zero Slip Length: Universal Benchmark Data for 3D in Silico, in Vitro and in Vivo Experiments 

2021 ◽  
Author(s):  
V R Sanal Kumar ◽  
Vigneshwaran Sankar ◽  
Nichith Chandrasekaran ◽  
Sulthan Ariff Rahman Mohamed Rafic ◽  
Ajith Sukumaran ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Fluid Flow ◽  
Closed Form ◽  
Slip Length ◽  
Pressure Ratio ◽  
Flow Choking ◽  
Benchmark Data ◽  
Nanoscale Fluid Flow

Abstract Although the interdisciplinary science of nanotechnology has been advanced significantly over the last few decades there were no closed-form analytical models to predict the three-dimensional (3D) boundary-layer-blockage (BLB) factor, of diabatic flows (flows involves the transfer of heat) passing through a nanoscale tube. As the pressure of the diabatic nanofluid and/or non-continuum-flows rises, average-mean-free-path diminishes and thus, the Knudsen number lowers heading to a zero-slip wall-boundary condition with the compressible viscous flow regime in the nano scale tubes leading to Sanal flow choking [PMCID: PMC7267099; Physics of Fluids, DOI: 10.1063/5.0040440] creating a physical situation of the sonic-fluid-throat effect in the tube at a critical-total-to-static pressure ratio (CPR). Herein, we presented a closed-form-analytical-model, which is capable to predict exactly the 3D-BLB factor at the Sanal flow choking-condition of nanoscale diabatic fluid flow systems at the zero-slip-length. The innovation of Sanal flow choking model in the nanoscale fluid flow system is established herein through the entropy relation, as it satisfies all the conservation laws of nature. The exact value of the 3D-BLB factor in the sonic-fluid-throat region presented herein for each gas is a universal benchmark data for performing high-fidelity in silico, in vitro and in vivo experiments for the lucrative design optimization of nanoscale fluid flow systems in gravity and microgravity environments and also for drug discovery for prohibiting asymptomatic cardiovascular diseases in Earth and human spaceflight <doi.org/10.2514/6.2021-0357>. Note that the relatively high and low-blood-viscosity (creating high turbulence) leads to the Sanal flow choking causing asymptomatic cardiovascular diseases. Such diseases in the cardiovascular system can be negated by maintaining the systolic-to-diastolic blood pressure ratio lower than the CPR <10.1002/gch2.202000076>. The CPR is regulated by the heat capacity ratio (HCR) of the fluid. Note that HCR is the key parameter, which could control simultaneously blood viscosity and turbulence. The physical insight of the boundary-layer-blockage persuaded nanoscale Sanal flow choking in diabatic flows presented in this article sheds light on finding solutions to numerous unresolved scientific problems in physical, chemical and biological systems carried forward over the centuries because the closed-form analytical model describing the phenomenon of Sanal flow choking is a unique scientific language of the real-world-fluid flows. More specifically, mathematical models presented herein are capable to forecast the limiting conditions of deflagration to detonation transition (DDT) in nanoscale systems and beyond with confidence. Additionally, the Sanal flow choking condition will forecast the asymptomatic-hemorrhage and acute-heart-failure https://www.ahajournals.org/doi/10.1161/str.52.suppl_1.P804. Briefly, the undesirable Sanal flow choking causing detonation and hemorrhagic stroke can be negated by increasing the HCR of the fluid.

scholarly journals Microvasculature-on-a-Chip: Bridging the interstitial blood-lymph interface via mechanobiological stimuli

2021 ◽  
Author(s):  
Barbara Bachmann ◽  
Sarah Spitz ◽  
Christian Jordan ◽  
Patrick Schuller ◽  
Heinz D Wanzenboeck ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Fluid Flow ◽  
Interstitial Fluid ◽  
Lymphatic System ◽  
Immune Cell ◽  
Scientific Progress ◽  
Morphological Characteristics ◽  
Interstitial Fluid Flow

After decades of simply being referred to as the body's sewage system, the lymphatic system has recently been recognized as a key player in numerous physiological and pathological processes. As an essential site of immune cell interactions, the lymphatic system is a potential target for next-generation drug delivery approaches in treatments for cancer, infections, and inflammatory diseases. However, the lack of cell-based assays capable of recapitulating the required biological complexity combined with unreliable in vivo animal models currently hamper scientific progress in lymph-targeted drug delivery. To gain more in-depth insight into the blood-lymph interface, we established an advanced chip-based microvascular model to study mechanical stimulation's importance on lymphatic sprout formation. Our microvascular model's key feature is the co-cultivation of spatially separated 3D blood and lymphatic vessels under controlled, unidirectional interstitial fluid flow while allowing signaling molecule exchange similar to the in vivo situation. We demonstrate that our microphysiological model recreates biomimetic interstitial fluid flow, mimicking the route of fluid in vivo, where shear stress within blood vessels pushes fluid into the interstitial space, which is subsequently transported to the nearby lymphatic capillaries. Results of our cell culture optimization study clearly show an increased vessel sprouting number, length, and morphological characteristics under dynamic cultivation conditions and physiological relevant mechanobiological stimulation. For the first time, a microvascular on-chip system incorporating microcapillaries of both blood and lymphatic origin in vitro recapitulates the interstitial blood-lymph interface.

scholarly journals Calcium Signaling in Bone Cell Networks Induced by Fluid Flow

2009 ◽  
Author(s):  
X. Lucas Lu ◽  
Bo Huo ◽  
Andrew D. Baik ◽  
X. Edward Guo
Keyword(s):  
Fluid Flow ◽  
Microcontact Printing ◽  
Bone Cell ◽  
Molecular Pathways ◽  
Mechanical Stimuli ◽  
Adaptive Responses ◽  
Cell Network ◽  
Cell Networks

Mechanical stimuli such as fluid flow can induce robust multiple intracellular calcium ([Ca2+]i) peaks in connected bone cell networks [1]. This fluid flow induced oscillation of [Ca2+]i can come from two sources: intracellular Ca2+ stores (e.g., endoplasmic reticulum, ER) and the extracellular environment. Moreover, [Ca2+]i signaling is mediated by various molecular pathways, such as IP3, ATP, PGE2, and NO. Osteocytes are believed to comprise a sensory network in bone tissue that monitors in vivo mechanical loading and triggers appropriate adaptive responses from osteoblasts and osteoclasts [2]. It is also well recognized that osteoblasts, the cells responsible for bone formation, can directly sense and respond to mechanical stimulation (e.g., fluid flow). In the present study, two types of cell networks were constructed in vitro with osteocyte-like and osteoblast-like cells, respectively, by using microcontact printing and self assembled monolayer (SAM) technologies. The calcium responses of the two types of cell networks to fluid flow were recorded, quantitatively analyzed, and compared. Then we examined how the [Ca2+]i response in the osteocyte cell network was influenced by gap junctions, intra/extracellular calcium sources, and other various molecular pathways.

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